Hot and cold beverages and food (e.g., coffee, tea, soft drinks, soup, ice cream, and the like) may present a handling problem to consumers when dispensed into containers such as drinking cups. For example, paper, plastic, and foam drinking cups often do not provide sufficient thermal insulating properties when filled with hot or cold beverages. As a result, handling of such containers may be uncomfortable to the consumer.
Disposable cups are routinely used in fast food and roadside restaurants to contain both hot and cold drinks. Because such cups have relatively thin walls, insulation is poor. As a result, the cups in which hot beverages are served are often too hot to hold comfortably, and the outside surface of cups in which cold beverages are served often accumulate moisture, also making the cups difficult to hold, thus causing the holder's hand and the table to become wet. In addition, cold drinks warm quickly and hot drinks lose heat rapidly.
In response to the need for a better beverage insulator, various types of disposable cardboard and paper sleeves have been used. The sleeves are sized to slide onto the outside of a beverage cup and are held in place by friction and sometimes a thermoplastic coating as in U.S. Pat. Nos. 5,826,786 and 5,205,473. The wide diameter end of the typical beverage cup prevents the sleeve from sliding off the cup while the cup is being held.
In an effort to provide adequate insulation for comfortable handling of a paper cup, the art has proposed many versions of an insulating sleeve for holding the cup. These sleeves are frequently made from a paperboard blank that is configured to closely embrace the paper cup and protect the user's fingers from high temperatures. These sleeves, being disposable like the cup itself, still represent a much smaller burden on the environment than does an extra cup frequently used for this purpose.
One such insulating sleeve, disclosed in U.S. Pat. No. 5,425,497 to Sorensen, is made from an arcuate blank or band with oppositely extending slots at the ends, for joining the ends together, the band being of a sheet material characterized by a plurality of discrete, spaced-apart, approximately hemispherically-shaped depressions covering substantially the entire surface of the band, thus creating a plurality of insulating air gaps between the band and a cup around which the band is placed. Another such sleeve, disclosed in U.S. Pat. No. 5,842,633 to Nurse, is an arcuate band of flexible corrugated material with curved side walls, oppositely extending slots adjacent the ends of the band and tabs lying alongside the slots, the tabs projecting only part-way across the width of the band, to facilitate the setting up of the sleeve.
These configurations suffer from several drawbacks. In order to be used for holding a cup, the flat arcuate band must be rolled into a circle and its notched ends must be interlocked to form a tapered sleeve for holding the cup. This type of cup holder sleeve has the disadvantage that it must be assembled on site by the food service worker or the customer, which can be inconvenient and take additional time during food service. In addition, the need to interlock the notched ends on-site risks possible breakage or improper assembly. Various other types of sleeves that also require on-site assembly of opposing ends, such as with a fastener, e.g., a pressure-sensitive strip, have similar disadvantages.
Still other configurations have been devised that require no on-site assembly other than changing the configuration of the sleeve from a folded, stored position to an open position. For example, in U.S. Pat. No. 5,454,484 to Chelossi, the insulating sleeve is made from a folded arcuate paper stock blank whose ends have been adhered or glued to each other. This folded sleeve, which expands to an oval or eye like shape by squeezing the folded sleeve at the folds, thereby providing an opening to receive the bottom end of a tapered beverage cup, has become the standard in the field.
Other alternatives have also been proposed, such as cup sleeves disclosed in U.S. Pat. No. 3,908,523 to Shikaya, U.S. Pat. No. 5,205,473 to Coffin, Sr. and U.S. Pat. No. 5,222,656 to Carlson. The Shikaya '523 and Coffin, Sr. '473 patents each suggest providing thermal insulating sleeves for beverage cups having generally longitudinally oriented corrugations. The Carlson '656 patent suggests forming a tubular insulating sleeve from a felt-like material.
Another insulating sleeve for drink cups has been proposed in U.S. Pat. No. 5,667,135, which is embodied in a “honeycombed” insulative sleeve for a beverage cup side wall. The sleeve includes a plurality of circumferentially spaced-apart rows of generally longitudinally oriented and off-set slits. The slits thereby allow the sleeve to expand circumferentially when positioned on a portion of the beverage cup side wall and, by virtue of such circumferential expansion, to thereby form an insulative honeycomb structure therearound.
In still another patent, U.S. Pat. No. 6,986,438 to Leung, a sleeve is disclosed having a plurality of slits cut at least partway across the sleeve from the top edge of the sleeve, each slit comprising an entry point at the top edge of the sleeve and a terminal point at least partway across the sleeve. The cut out region has a width greater than the width of the slit. The cut out region is provided within the sleeve body at the terminal point of each slit. The result is that, when the container is inserted into the sleeve, the slits allow said top edge of the sleeve to spread so that the sleeve at least partially conforms to the container.
In the case of all pre-assembled sleeves, the final sleeve size is fixed and permanent so that it will fit standard cups of a specific taper and, as a result, the sleeve's position on a cup is pre-determined by the sleeve size and the cup taper. Generally this has been market accepted as long as the cups are consistent as to size and taper. It has been proposed to use an adhesive or a heat-activated coating to attempt to maximize cup adherence, and thus minimize the tendency of the sleeves to separate from the cup. This has been proved to be only marginally effective, especially in sleeves made with corrugated material, in which case the adhesive, without any intervention, seeps out of the bottom of the corrugated flutes.